Indoor plumbing including metal pipes dates at least to ancient Rome. The Romans also implemented hot water heating systems, called hypocausts, which were used extensively in large communal baths. See, e.g., Nova Online, Secrets of Lost Empires, Roman Bath, A Day at the Baths, Part 6 (Caldarium) November 2000, available at http://www.pbs.org/wgbh/nova/lostempires/roman/day.html, accessed Mar. 17, 2013.
Modern plumbing systems implement many of the same techniques pioneered in Ancient Rome. As in Ancient Rome, hot water “burners” heat a container of water from below to elevate its temperature in buildings in the United States. Modern systems also use pipes to deliver water, with some refinements in materials and workmanship to improve their performance. Metal pipes, such as copper or brass, are still in use, but effective advanced materials have also been developed, such as cross-linked polyethylene (“PEX”). In the plumbing industry, copper pipes are still heralded as having many advantages over PEX, including greater durability (especially in outdoor environments) and resistance to contamination.
In homes with longer distances between hot water burners (and their associated hot water storage tanks) and served fixtures, the connecting pipes have enough length to create a substantial hot water service lag. After opening a hot water tap, hot water in the associated pipe has cooled in the wall over its entire length outside of the tank, and a user must wait until new hot water from the tank reaches the fixture. To combat this lag, hot water recirculation systems have been developed. In their simplest form, hot water recirculation systems may create a short bridge between the hot and cold services (typically, at the fixture in the circuit farthest away from the tank) to continuously supply new hot water to the points of service. A pump may be used, or, if the pipes are arranged properly (hot water service pipe at a lower level) the system may move water through the circuit continuously as a heat siphon. More complex systems for hot water recirculation involve additional pipes run out to fixtures, to complete such “on demand” hot water availability. Another form of lag-reduction technology is known as a “Home Run” or “manifold” system, where much smaller gauge pipes are run out to each fixture, individually, to reduce the amount of water to clear when a hot water tap is opened, and, therefore, the amount of hot water lag in using one fixture. However, home run systems may, ironically, create lag in some instances due to their separated structure, such as when multiple fixtures are in use on or about the same time. Nonetheless, all of these systems create substantial convenience for a user.
Antiseptic soaps have also been used in bathrooms, among many other rooms and uses, for quite some time. In general, hand washing, particularly before consuming or preparing food, is highly recommended by the medical community as among the best ways to fight the risk of several illnesses, such as the flu.
It should be understood that the disclosures in this application related to the background of the invention, in, but not limited to this section titled “Background,” do not necessarily set forth prior art or other known aspects exclusively, and may instead include art that was invented concurrently or after the present invention and conception, and details of the inventor's own discoveries and work results.